Iran Press/Asia: Chief Inspector Shellamae Chang, spokesman for the Zamboanga police, identified those killed as Habil Rex, 46, and Bato Sattal, 47. Both were said to be preachers at the mosque.
An unidentified suspect reportedly turned off a nearby streetlight and lobbed a grenade at the mosque, in Talon district, where about 10 people were sleeping, just past midnight on Wednesday, the Straits Times reported.
One investigator told online news site Rappler that a safety lever of a Belgian-made grenade was recovered at the scene.
The Inquirer reported that the mosque was owned by a retired police official.
In a statement, the Ulama Council of Zamboanga Peninsula called the attack "devilish, irrational and inhumane".
This comes just two days after twin blasts rocked a Roman Catholic cathedral on Jolo island, west of Zamboanga, and left at least 20 dead and more than 100 injured.
Related News:
19 killed, dozens injured in Philippines cathedral explosion
Rommel Banlaoi, executive director of the Philippine Institution for Peace, Violence and Terrorism Research, told ABS-CBN News Channel that he does not doubt ISIS' claim 'because the target is a cathedral'.
"Local terrorist organisations will not dare mount such a kind of mass casualty attack against Christian symbols, particularly cathedrals. Only ISIS has that kind of motivation to target cathedrals and to target Christian communities," he said. 101/202
Read More:
At least 44 militants killed in clashes in the philippines
'
